public GuessResult makeAGuess(MastermindNumber numberOfGuess) {

        String secrect = this.secretNumber.toString();
        String guess = numberOfGuess.toString();

        int correctpos = 0;
        int incorrectpos = 0;

        // iterate the guess to match the secret
        for (int i = 0; i < guess.length(); i++) {

            // is the number present in the secret, contains cant handle single chars, so we have to simulate the contains
            if(secrect.indexOf(guess.charAt(i)) > -1) {

                // is it the same position?
                if (secrect.charAt(i) == guess.charAt(i)) {
                    correctpos++;
                } // otherwise the number is only present but not on the correct position
                else {
                    incorrectpos++;
                }

            }
        }

        this.guessResult = new GuessResult(correctpos, incorrectpos);
        return this.guessResult;

    }